Back contact cell and photovoltaic module

Abstract

The invention relates to a back contact cell and a photovoltaic module. The back contact battery comprises a battery piece body, a plurality of first grid lines, a plurality of second grid lines and a plurality of bonding pads, the battery piece body is provided with a front face and a back face which are arranged oppositely in the thickness direction perpendicular to the battery piece body, the first grid lines and the second grid lines are arranged on the back face, and the first grid lines and the second grid lines are arranged alternately; the plurality of bonding pads are arranged on the back surface and comprise a plurality of first bonding pads and a plurality of second bonding pads; the first bonding pad is electrically connected with the first grid line, and the second bonding pad is electrically connected with the second grid line. Wherein the plurality of first bonding pads comprise first test bonding pads, the first test bonding pads are in electric contact with at least two adjacent first grid lines, the plurality of second bonding pads comprise second test bonding pads, and the second test bonding pads are in electric contact with at least two adjacent second grid lines. The test reliability of the back contact battery can be improved.

Description

Technical Field

[0001] This application relates to the technical field of back contact batteries, and particularly to a back contact battery and a photovoltaic module. Background Art

[0002] In related technologies, after manufacturing a back contact battery, it is usually necessary to test the back contact battery. Therefore, how to improve the test reliability of the back contact battery has become an urgent problem to be solved. Summary of the Invention

[0003] Based on this, it is necessary to provide a back contact battery and a photovoltaic module for the above technical problems, which can improve the test reliability of the back contact battery.

[0004] According to a first aspect of the present application, there is provided a back contact battery, including:

[0005] A battery cell main body, along the thickness direction perpendicular to the battery cell main body, the battery cell main body has a front surface and a back surface arranged opposite to each other;

[0006] A plurality of first grid lines and a plurality of second grid lines, arranged on the back surface, and the first grid lines and the second grid lines are alternately arranged; and

[0007] A plurality of pads, arranged on the back surface, and including a plurality of first pads and a plurality of second pads; the first pads are electrically connected to the first grid lines, and the second pads are electrically connected to the second grid lines;

[0008] Wherein, the plurality of first pads include a first test pad, and the first test pad is in electrical contact with at least two adjacent first grid lines;

[0009] The plurality of second pads include a second test pad, and the second test pad is in electrical contact with at least two adjacent second grid lines.

[0010] In one embodiment, the plurality of pads are arranged in rows and columns; the pads are provided with n columns, and the first test pad is located in at least one column among the 2nd column to the (n - 1)th column; the second test pad is located in at least one column among the 2nd column to the (n - 1)th column and is in a different column from the first test pad; wherein, n is a positive integer, 10 ≤ n ≤ 20; and / or

[0011] The plurality of pads are arranged in rows along a first direction and in columns along a second direction; the pads are provided with m rows; the battery cell main body has a straight edge and a chamfered edge oppositely arranged along the second direction; along the direction from the chamfered edge to the straight edge, the first test pad is located in one row among the 2nd row to the mth row; the second test pad is located in one row among the 2nd row to the mth row; wherein, m is a positive integer, 2 ≤ m ≤ 6; and / or

[0012] The plurality of first pads further includes a plurality of first connection pads; the orthographic projection area of the first test pad on the main body of the cell is larger than the orthographic projection area of the first connection pad on the main body of the cell; and / or

[0013] The plurality of second pads further includes a plurality of second connection pads; the orthographic projection area of the second test pad on the main body of the cell is larger than the orthographic projection area of the second connection pad on the main body of the cell;

[0014] Wherein, the first direction and the second direction intersect with each other and are both perpendicular to the thickness direction of the main body of the cell.

[0015] In one embodiment, the first grid lines and the second grid lines both extend along the first direction; the plurality of first pads further includes a plurality of first connection pads; the dimension of the first test pad in the second direction is larger than the dimension of the first connection pad in the second direction; the plurality of second pads further includes a plurality of second connection pads; the dimension of the second test pad in the second direction is larger than the dimension of the second connection pad in the second direction; wherein, the first direction and the second direction intersect with each other and are both perpendicular to the thickness direction of the main body of the cell;

[0016] The dimension of the first test pad in the second direction is 2 mm - 4 mm, and the dimension of the first test pad in the first direction is 0.2 mm - 3.0 mm; and / or

[0017] The dimension of the second test pad in the second direction is 2 mm - 4 mm, and the dimension of the second test pad in the first direction is 0.2 mm - 3.0 mm; and / or

[0018] The plurality of first pads includes a plurality of first connection pads; the dimension of the first connection pad in the second direction is 0.3 mm - 3.0 mm, and the dimension of the first connection pad in the first direction is 0.2 mm - 3.0 mm; and / or

[0019] The plurality of second pads includes a plurality of second connection pads; the dimension of the second connection pad in the second direction is 0.3 mm - 3.0 mm, and the dimension of the second connection pad in the first direction is 0.2 mm - 3.0 mm.

[0020] In one embodiment, the back contact battery further includes a plurality of third grid lines and a plurality of fourth grid lines; the third grid lines and the fourth grid lines are alternately disposed on the back surface of the battery cell body along a first direction, and both extend along a second direction; the first grid line and the second grid line both extend along the first direction; the third grid line is electrically connected to the first grid line; the fourth grid line is electrically connected to the second grid line; wherein, the first direction and the second direction intersect with each other and are both perpendicular to the thickness direction of the battery cell body.

[0021] In one embodiment, both the third grid line and the fourth grid line include a plurality of first portions connected along the second direction;

[0022] The first portion has a first end and a second end oppositely disposed along the second direction;

[0023] The dimension of the first end in the first direction is different from the dimension of the second end in the first direction;

[0024] Adjacent two of the first ends of two adjacent first portions are connected; or adjacent two of the second ends of two adjacent first portions are connected.

[0025] In one embodiment, the dimension of the first end in the first direction is greater than the dimension of the second end in the first direction;

[0026] The orthographic projection of the first end on a target plane overlaps with the orthographic projection of the corresponding pad on the target plane; the orthographic projection of the second end on the target plane is offset from the orthographic projection of the corresponding pad on the target plane; the target plane is perpendicular to the thickness direction of the battery cell body;

[0027] The dimension of the first end in the first direction is 0.2 mm - 1.8 mm, and the dimension of the second end in the first direction is 0.02 mm - 1.6 mm.

[0028] In one embodiment, the plurality of third grid lines include a first edge grid line and a plurality of first intermediate grid lines electrically connected to the first edge grid line, the plurality of fourth grid lines include a second edge grid line and a plurality of second intermediate grid lines electrically connected to the second edge grid line, along the first direction, the first intermediate grid lines and the second intermediate grid lines are alternately disposed and are located between the first edge grid line and the second edge grid line;

[0029] The back contact battery further includes a plurality of fifth grid lines and a plurality of sixth grid lines extending along the first direction, the fifth grid lines and the sixth grid lines are alternately disposed;

[0030] The first gate line and the fifth gate line are alternately arranged along the first direction, and are both electrically connected to the first edge gate line; along the second direction, the first gate line and the sixth gate line are alternately arranged;

[0031] The second gate line and the sixth gate line are alternately arranged along the first direction, and are both electrically connected to the second edge gate line; along the second direction, the second gate line and the fifth gate line are alternately arranged;

[0032] A plurality of adjacent first gate lines along the second direction are in electrical contact with the same first intermediate gate line;

[0033] A plurality of adjacent second gate lines along the second direction are in electrical contact with the same second intermediate gate line.

[0034] In one embodiment, part of the fifth gate line includes a first sub-gate line and a second sub-gate line that are spaced apart along the first direction; both the first sub-gate line and the second sub-gate line are electrically connected to the first gate line; the second intermediate gate line is located between the first sub-gate line and the second sub-gate line of the adjacent fifth gate line along the first direction, so as to be electrically isolated from the fifth gate line; the second pad is located between the first sub-gate line and the second sub-gate line of the adjacent fifth gate line along the first direction, so as to be electrically isolated from the fifth gate line;

[0035] Part of the sixth gate line includes a third sub-gate line and a fourth sub-gate line that are spaced apart along the first direction; both the third sub-gate line and the fourth sub-gate line are electrically connected to the second gate line; the first intermediate gate line is located between the third sub-gate line and the fourth sub-gate line of the adjacent sixth gate line along the first direction, so as to be electrically isolated from the sixth gate line; the first pad is located between the third sub-gate line and the fourth sub-gate line of the adjacent sixth gate line along the first direction, so as to be electrically isolated from the sixth gate line.

[0036] In one embodiment, the back contact battery further includes a seventh gate line and an eighth gate line; the plurality of pads further includes a plurality of third pads and a plurality of fourth pads; along the first direction, the plurality of first pads and the plurality of second pads are located between the plurality of third pads and the plurality of fourth pads; the plurality of third pads and the first edge gate line are spaced apart along the first direction on one side of the battery chip body along the first direction, and the third pad is electrically connected to the first edge gate line through the seventh gate line; the plurality of fourth pads and the second edge gate line are spaced apart along the first direction on the other side of the battery chip body along the first direction, and the fourth pad is electrically connected to the second edge gate line through the eighth gate line.

[0037] In one embodiment, the back-contact battery further includes a ninth grid line; the plurality of fifth grid lines are arranged in rows and columns, and among the columns of the fifth grid lines closest to the second edge grid line along the first direction, the fifth grid lines including the first sub-grid line and the second sub-grid line are defined as first target grid lines, the first sub-grid line of the first target grid line is electrically connected to the first grid line, and the second sub-grid line of the first target grid line is electrically connected to the first grid line through the adjacent ninth grid line and fifth grid line; the fourth pad is arranged between the first sub-grid line and the second sub-grid line of the adjacent first target grid line along the first direction; and / or

[0038] The back-contact battery further includes a tenth grid line; the plurality of sixth grid lines are arranged in rows and columns, and among the columns of the sixth grid lines closest to the first edge grid line along the first direction, the sixth grid lines including the third sub-grid line and the fourth sub-grid line are defined as second target grid lines; the third sub-grid line of the second target grid line is electrically connected to the second grid line, and the fourth sub-grid line of the second target grid line is electrically connected to the second grid line through the adjacent tenth grid line and sixth grid line; the third pad is arranged between the third sub-grid line and the fourth sub-grid line of the adjacent second target grid line along the first direction.

[0039] In one embodiment, the back-contact battery further includes at least two positioning marks provided on the battery chip body;

[0040] The plurality of first grid lines and the plurality of second grid lines are arranged on the battery chip body at preset positions by means of the at least two positioning marks;

[0041] The at least two positioning marks are symmetrically distributed with reference to a first preset plane;

[0042] The distance between the centers of two adjacent positioning marks along the first direction is a first preset distance;

[0043] In two back-contact batteries symmetrically arranged with reference to a second preset plane, the distance between the centers of two adjacent positioning marks along the second direction is a second preset distance;

[0044] Wherein, the first preset plane is perpendicular to the first direction, the second preset plane is perpendicular to the second direction, the first direction and the second direction intersect with each other, and both are perpendicular to the thickness direction of the battery chip body;

[0045] The first preset distance is 110 mm - 130 mm;

[0046] The second preset distance is 110 mm - 130 mm.

[0047] In one embodiment, the at least two positioning marks include at least two first positioning marks and at least two second positioning marks;

[0048] The preset positions include a first preset position corresponding to the plurality of first grid lines and a second preset position corresponding to the plurality of second grid lines; the plurality of first grid lines are arranged on the battery chip body according to the first preset position by means of the at least two first positioning marks; the plurality of second grid lines are arranged on the battery chip body according to the second preset position by means of the at least two second positioning marks; and / or

[0049] The orthographic projection of the positioning mark on the battery chip body is configured as a circle, and the diameter of the circle is 0.01 mm - 2 mm; and / or

[0050] The plurality of first grid lines are arranged in rows and columns; the first grid line has a first axis of symmetry parallel to the first direction; the orthographic projection of the center of the first positioning mark on the battery chip body coincides with the orthographic projection of the first axis of symmetry of the corresponding row of the first grid lines on the battery chip body; and / or

[0051] The plurality of second grid lines are arranged in rows and columns; the second grid line has a second axis of symmetry parallel to the first direction; the orthographic projection of the center of the second positioning mark on the battery chip body coincides with the orthographic projection of the second axis of symmetry of the corresponding row of the second grid lines on the battery chip body.

[0052] According to a second aspect of the present application, a photovoltaic module is provided, including a battery string, and the battery string includes a plurality of back contact batteries according to any one of the above embodiments.

[0053] In the technical solution of the present application, the positive electrode and the negative electrode of the test device can be respectively connected to the first test pad and the second test pad, and the first test pad is in electrical contact with at least two first grid lines, and the second test pad is in electrical contact with at least two second grid lines. Therefore, while the back contact battery can be tested by using the test device, the electrical connection reliability between the first test pad and the battery chip body can be improved, and the electrical connection reliability between the second test pad and the battery chip body can also be improved, thereby improving the test reliability of the back contact battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Shows a schematic structural diagram of a back contact battery in an embodiment of the present application (when an insulating layer is provided).

[0055] Figure 2 Shows a schematic structural diagram of a back contact battery in an embodiment of the present application (when no insulating layer is provided).

[0056] Figure 3 The structural schematic diagram of two first parts in an embodiment of the present application is shown.

[0057] Figure 4 The structural schematic diagram of two first parts in another embodiment of the present application is shown.

[0058] Figure 5 The structural schematic diagram of two first parts in yet another embodiment of the present application is shown.

[0059] Figure 6 Shows Figure 1 The enlarged schematic diagram at A1 of

[0060] Figure 7 Shows Figure 1 The enlarged schematic diagram at A2 of

[0061] Figure 8 Shows Figure 1 The enlarged schematic diagram at A3 of

[0062] Figure 9 Shows Figure 1 The enlarged schematic diagram at A4 of

[0063] Figure 10 Shows Figure 1 The enlarged schematic diagram at A5 of

[0064] Figure 11 The structural schematic diagram of two back-contact batteries in an embodiment of the present application is shown.

[0065] Reference numerals: 10, back-contact battery; 100, main body of the battery cell; 101, first edge; 102, second edge; 103, straight edge; 104, chamfered edge; 210, first grid line; 220, second grid line; 230, third grid line; 240, fourth grid line; 231, first edge grid line; 232, first intermediate grid line; 233, first part; 2331, first end; 2332, second end; 241, second edge grid line; 242, second intermediate grid line; 250, fifth grid line; 251, first sub-grid line; 252, second sub-grid line; 260, sixth grid line; 261, third sub-grid line; 262, fourth sub-grid line; 270, seventh grid line; 280, eighth grid line; 291, ninth grid line; 292, tenth grid line; 293, eleventh grid line; 294, twelfth grid line; 310, first pad; 311, first test pad; 312, first connection pad; 320, second pad; 321, second test pad; 322, second connection pad; 330, third pad; 340, fourth pad; C1, first spacer groove; C2, second spacer groove; 400, positioning mark; 410, first positioning mark; 420, second positioning mark; P1, first preset plane; P2, second preset plane; 510, first insulating part; 520, second insulating part; 530, third insulating part; 540, fourth insulating part. Detailed implementation manners

[0066] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0067] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0068] In addition, if the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0069] In this application, unless otherwise clearly specified and limited, if terms such as "installed", "connected", "joined", "fixed", etc. appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0070] In this application, unless otherwise clearly specified and limited, if there is a description such as a first feature being "on" or "under" a second feature, the meaning can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature can mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath", and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0071] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right", and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0072] Figure 1 The structural schematic diagram of the back contact battery 10 in an embodiment of this application is shown (when an insulating layer is provided), Figure 2 The structural schematic diagram of the back contact battery 10 in an embodiment of this application is shown (when no insulating layer is provided).

[0073] Please refer to Figure 1 and Figure 2, an embodiment of the present application provides a back-contact battery 10, including a battery cell body 100, a plurality of first grid lines 210, a plurality of second grid lines 220, and a plurality of pads.

[0074] Along the thickness direction perpendicular to the battery cell body 100, the battery cell body 100 has a front surface and a back surface arranged opposite to each other. The plurality of first grid lines 210 and the plurality of second grid lines 220 are arranged on the back surface, and the first grid lines 210 and the second grid lines 220 are arranged alternately.

[0075] Optionally, the plurality of first grid lines 210 and the plurality of second grid lines 220 are arranged in rows along a first direction F1 and in columns along a second direction F2. The first direction F1 and the second direction F2 intersect with each other and are perpendicular to the thickness direction of the battery cell body 100. The first grid lines 210 and the second grid lines 220 are arranged alternately along the first direction F1 and also arranged alternately along the second direction F2.

[0076] Specifically, the first direction F1 and the second direction F2 are perpendicular to each other and both perpendicular to the thickness direction of the battery cell body 100. One of the first direction F1 and the second direction F2 is the length direction of the battery cell body 100, and the other of the first direction F1 and the second direction F2 is the width direction of the battery cell body 100. By way of example, the first direction F1 is the length direction of the battery cell body 100, and the second direction F2 is the width direction of the battery cell body 100.

[0077] Both the first grid lines 210 and the second grid lines 220 are sub-grid lines. The back-contact battery 10 of the present application can be a back-contact battery 10 without a main grid or a back-contact battery 10 with a main grid, and no specific limitation is made here.

[0078] The plurality of pads are arranged on the back surface, and the plurality of pads include a plurality of first pads 310 and a plurality of second pads 320. The first pads 310 are electrically connected to the first grid lines 210, and the second pads 320 are electrically connected to the second grid lines 220. Among them, the plurality of first pads 310 include a first test pad 311, and the first test pad 311 is in electrical contact with at least two adjacent first grid lines 210. The plurality of second pads 320 include a second test pad 321, and the second test pad 321 is in electrical contact with at least two adjacent second grid lines 220.

[0079] Specifically, the orthographic projection of the first test pad 311 on the battery cell body 100 overlaps with the orthographic projections of at least two adjacent first grid lines 210 on the battery cell body 100, and the orthographic projection of the second test pad 321 on the battery cell body 100 overlaps with the orthographic projections of at least two adjacent second grid lines 220 on the battery cell body 100.

[0080] The back-contact battery 10 of the present application can be tested by a test device. The positive electrode and the negative electrode of the test device can be respectively connected to the first test pad 311 and the second test pad 321. Combining that the first test pad 311 is in electrical contact with at least two first grid lines 210, and the second test pad 321 is in electrical contact with at least two second grid lines 220. Therefore, while the back-contact battery 10 can be tested by the test device, the electrical connection reliability between the first test pad 311 and the battery cell body 100 can be improved, and the electrical connection reliability between the second test pad 321 and the battery cell body 100 can also be improved. Furthermore, the test reliability of the back-contact battery 10 can be improved.

[0081] In some embodiments, multiple pads are arranged in rows and columns, and the pads are provided with n columns. The first test pad 311 is located in at least one column among the second column to the (n - 1)th column, and the second test pad 321 is located in at least one column among the second column to the (n - 1)th column and is in a different column from the first test pad 311. Wherein, n is a positive integer, 10 ≤ n ≤ 20. Specifically, n can be an even number, such as n can be 10, 12, 14, 16, 18 or 20, etc.

[0082] Exemplarily, n is 10. Both the first grid line 210 and the second grid line 220 extend along the first direction F1. The battery cell body 100 has a first edge 101 and a second edge 102 that are oppositely arranged along the first direction F1. There are two first test pads 311. Along the first direction F1, compared with the second edge 102, one of the first test pads 311 is closer to the first edge 101. Along the direction from the first edge 101 to the second edge 102, this first test pad 311 is located in the third column. Along the first direction F1, compared with the first edge 101, the other first test pad 311 is closer to the second edge 102. Along the direction from the second edge 102 to the first edge 101, this first test pad 311 is located in the fourth column.

[0083] In this way, both of the two first test pads 311 are located in the middle columns, which is convenient for better collecting the current of all the first grid lines 210 by using the two first test pads 311, and further is beneficial to the test reliability of the back-contact battery 10.

[0084] Exemplarily, n is 10, and the main body 100 of the battery cell has a first edge 101 and a second edge 102 oppositely arranged along the first direction F1. There are two second test pads 321. Along the first direction F1, compared with the first edge 101, one of the second test pads 321 is closer to the second edge 102. Along the direction from the second edge 102 to the first edge 101, this second test pad 321 is located in the third column. Along the first direction F1, compared with the first edge 101, the other second test pad 321 is closer to the first edge 101. Along the direction from the first edge 101 to the second edge 102, this second test pad 321 is located in the fourth column.

[0085] In this way, both of the two second test pads 321 are located in the middle columns, which is convenient for better collecting the currents of all the second grid lines 220 by using the two second test pads 321, and thus is beneficial to the test reliability of the back contact battery 10. In some embodiments, multiple pads are arranged in rows along the first direction F1 and in columns along the second direction F2, and there are m rows of pads. The main body 100 of the battery cell has a straight edge 103 and a chamfered edge 104 oppositely arranged along the second direction F2. The first direction F1 and the second direction F2 are perpendicular to each other and both are perpendicular to the thickness direction of the main body 100 of the battery cell. The first test pad 311 is located in one of the rows from the second row to the m-th row, and the second test pad 321 is located in one of the rows from the second row to the m-th row. Wherein, m is a positive integer, and 2 ≤ m ≤ 6. m can be 2, 3, 4, 5 or 6.

[0086] Specifically, the first test pad 311 and the second test pad 321 are located in the same row.

[0087] Exemplarily, m is 5. Along the direction from the chamfered edge 104 to the straight edge 103, the first test pad 311 is located in the third row, and the second test pad 321 is located in the third row.

[0088] In this way, the first test pad 311 is located in the middle row, which is convenient for better collecting the currents of multiple first grid lines 210 by using the first test pad 311, and thus is beneficial to the test reliability of the back contact battery 10.

[0089] Similarly, the second test pad 321 is located in the middle row, which is convenient for better collecting the currents of multiple second grid lines 220 by using the second test pad 321, and thus is beneficial to the test reliability of the back contact battery 10.

[0090] In some embodiments, the multiple first pads 310 further include multiple first connection pads 312, and the orthographic projection area of the first test pad 311 on the main body 100 of the battery cell is larger than the orthographic projection area of the first connection pad 312 on the main body 100 of the battery cell.

[0091] In this way, it is beneficial for the first test pad 311 to be in electrical contact with more first grid lines 210, thereby improving the test reliability of the back contact battery 10.

[0092] In some embodiments, the plurality of second pads 320 further includes a plurality of second connection pads 322, and the orthographic projection area of the second test pad 321 on the battery cell body 100 is larger than the orthographic projection area of the second connection pad 322 on the battery cell body 100.

[0093] In this way, it is beneficial for the second test pad 321 to be in electrical contact with more second grid lines 220, thereby improving the test reliability of the back contact battery 10.

[0094] In some embodiments, both the first grid lines 210 and the second grid lines 220 extend along the first direction F1. The plurality of first pads 310 further includes a plurality of first connection pads 312, and the dimension of the first test pad 311 in the second direction F2 is larger than the dimension of the first connection pad 312 in the second direction F2. The plurality of second pads 320 further includes a plurality of second connection pads 322, and the dimension of the second test pad 321 in the second direction F2 is larger than the dimension of the second connection pad 322 in the second direction F2. Wherein, the first direction F1 intersects with the second direction F2, and both are perpendicular to the thickness direction of the battery cell body 100.

[0095] By setting the dimension of the first test pad 311 in the second direction F2 to be larger than the dimension of the first connection pad 312 in the second direction F2, combined with the fact that the first grid lines 210 extend along the first direction F1 intersecting with the second direction F2, in this way, it is beneficial for the first test pad 311 to be in electrical contact with more first grid lines 210, thereby improving the test reliability of the back contact battery 10.

[0096] By setting the dimension of the second test pad 321 in the second direction F2 to be larger than the dimension of the second connection pad 322 in the second direction F2, combined with the fact that the second grid lines 220 extend along the first direction F1 intersecting with the second direction F2, in this way, it is beneficial for the second test pad 321 to be in electrical contact with more second grid lines 220, thereby improving the test reliability of the back contact battery 10.

[0097] In some embodiments, the dimension of the first test pad 311 in the second direction F2 is 2 mm - 4 mm, and the dimension of the first test pad 311 in the first direction F1 is 0.2 mm - 3.0 mm.

[0098] Exemplarily, the dimension of the first test pad 311 in the second direction F2 is 2 mm, 3 mm or 4 mm, and the dimension of the first test pad 311 in the first direction F1 is 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm or 3.0 mm.

[0099] Set the size of the first test pad 311 in the second direction F2 within a suitable range, such as set to 2 mm - 4 mm, and set the size of the first test pad 311 in the first direction F1 within a suitable range, such as set to 0.2 mm - 3.0 mm. In this way, it is beneficial for the first test pad 311 to make electrical contact with more first grid lines 210, and the first test pad 311 can form sufficient surface contact with adjacent first grid lines 210, thereby improving the test reliability of the back contact battery 10.

[0100] The size of the second test pad 321 in the second direction F2 is 2 mm - 4 mm, and the size of the second test pad 321 in the first direction F1 is 0.2 mm - 3.0 mm.

[0101] Exemplarily, the size of the second test pad 321 in the second direction F2 is 2 mm, 3 mm or 4 mm, and the size of the second test pad 321 in the first direction F1 is 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm or 3.0 mm.

[0102] Set the size of the second test pad 321 in the second direction F2 within a suitable range, such as set to 2 mm - 4 mm, and set the size of the second test pad 321 in the first direction F1 within a suitable range, such as set to 0.2 mm - 3.0 mm. In this way, it is beneficial for the second test pad 321 to make electrical contact with more second grid lines 220, and the second test pad 321 can form sufficient surface contact with adjacent second grid lines 220, thereby improving the test reliability of the back contact battery 10.

[0103] In some embodiments, the plurality of first pads 310 includes a plurality of first connection pads 312. The size of the first connection pad 312 in the second direction F2 is 0.3 mm - 3.0 mm, and the size of the first connection pad 312 in the first direction F1 is 0.2 mm - 3.0 mm.

[0104] Exemplarily, the size of the first connection pad 312 in the second direction F2 is 0.3 mm, 1 mm, 2 mm or 3.0 mm, and the size of the first connection pad 312 in the first direction F1 is 0.2 mm, 1 mm, 2 mm or 3.0 mm.

[0105] In this way, the first connection pad 312 has sufficient area, which is convenient for improving the connection reliability between the first connection pad 312 and the first grid line 210, and is also convenient for improving the connection reliability between the first connection pad 312 and the following third grid line 230, and is also convenient for improving the connection reliability between the first connection pad 312 and the corresponding first solder tape (not shown in the figure).

[0106] The plurality of second pads 320 include a plurality of second connection pads 322. The size of the second connection pad 322 in the second direction F2 is 0.3 mm - 3.0 mm, and the size of the second connection pad 322 in the first direction F1 is 0.2 mm - 3.0 mm.

[0107] Exemplarily, the size of the second connection pad 322 in the second direction F2 is 0.3 mm, 1 mm, 2 mm or 3.0 mm, and the size of the second connection pad 322 in the first direction F1 is 0.2 mm, 1 mm, 2 mm or 3.0 mm.

[0108] Thus, the second connection pad 322 has sufficient area, which is convenient for improving the connection reliability between the second connection pad 322 and the second gate line 220, is also convenient for improving the connection reliability between the second connection pad 322 and the following fourth gate line 240, and is also convenient for improving the connection reliability between the second connection pad 322 and the corresponding second solder strip (not shown in the figure).

[0109] In some embodiments, the back contact battery 10 further includes a plurality of third gate lines 230 and a plurality of fourth gate lines 240. The third gate lines 230 and the fourth gate lines 240 are alternately disposed on the back surface of the battery chip body 100 along the first direction F1 and both extend along the second direction F2. The first gate line 210 and the second gate line 220 both extend along the first direction F1. The third gate line 230 is electrically connected to the first gate line 210, and the fourth gate line 240 is electrically connected to the second gate line 220. Wherein, the first direction F1 and the second direction F2 intersect with each other and are both perpendicular to the thickness direction of the battery chip body 100.

[0110] Specifically, both the third gate line 230 and the fourth gate line 240 are main gates.

[0111] The plurality of first gate lines 210 and the plurality of second gate lines 220 can be used to collect carriers of two different polarities of the battery chip body 100, and the plurality of third gate lines 230 can be used to collect the carriers collected by all the first gate lines 210, and the plurality of fourth gate lines 240 can also be used to collect the carriers collected by all the second gate lines 220. Thus, it is convenient to output the collected current through the plurality of third gate lines 230 and the plurality of fourth gate lines 240, the carrier collection ability of the back contact battery 10 can be improved, and the current collection efficiency of the back contact battery 10 can also be improved.

[0112] In some embodiments, both the third gate line 230 and the fourth gate line 240 include a plurality of first portions 233 connected along the second direction F2. The first portion 233 has a first end 2331 and a second end 2332 oppositely arranged along the second direction F2. The size of the first end 2331 in the first direction F1 is different from the size of the second end 2332 in the first direction F1.

[0113] It can be that two adjacent first ends 2331 of two adjacent first parts 233 are connected. Or it can be that two adjacent second ends 2332 of two adjacent first parts 233 are connected.

[0114] It can be, for example Figures 3 - 4 As shown, the orthographic projections of the first parts 233 of the third grid line 230 and the fourth grid line 240 on the battery cell body 100 are in the shape of an isosceles triangle or an isosceles trapezoid, etc. It can also be, for example Figure 5 As shown, the second ends 2332 of two first parts 233 are connected, and the orthographic projections of these two first parts 233 on the battery cell body 100 are in the shape of a narrow-waisted drum (concave inward).

[0115] Along the second direction F2, the dimensions of the third grid line 230 and the fourth grid line 240 in the first direction F1 show a changing trend. When using multiple third grid lines 230 to collect all the carriers collected by all the first grid lines 210 and using multiple fourth grid lines 240 to collect all the carriers collected by all the second grid lines 220, the occupied area of the third grid line 230 and the fourth grid line 240 can be reduced, thereby reducing the manufacturing cost of all the third grid lines 230 and all the fourth grid lines 240 (the material of the grid lines is usually silver, and the price of silver is relatively high. The design of the changing dimensions of the third grid line 230 and the fourth grid line 240 is beneficial to reducing the manufacturing cost of the third grid line 230 and the fourth grid line 240). In some embodiments, the dimension of the first end 2331 in the first direction F1 is greater than the dimension of the second end 2332 in the first direction F1. The orthographic projection of the first end 2331 on the target plane overlaps with the orthographic projection of the corresponding pad on the target plane; the orthographic projection of the second end 2332 on the target plane is offset from the orthographic projection of the corresponding pad on the target plane; the target plane is perpendicular to the thickness direction of the battery cell body 100.

[0116] It can be that the orthographic projection of the first end 2331 on the target plane overlaps with the orthographic projection of the adjacent first pad 310 on the target plane, and the orthographic projection of the second end 2332 connected to the first end 2331 on the target plane is offset from the orthographic projection of the first pad 310 on the target plane.

[0117] It can also be that the orthographic projection of the first end 2331 on the target plane overlaps with the orthographic projection of the adjacent second pad 320 on the target plane, and the orthographic projection of the second end 2332 connected to the first end 2331 on the target plane is offset from the orthographic projection of the second pad 320 on the target plane.

[0118] In this way, the first pad 310 can be connected to the first end 2331 of the corresponding third gate line 230, that is, the first pad 310 is connected to the position with a wider width on the corresponding third gate line 230; the second pad 320 can also be connected to the first end 2331 of the corresponding fourth gate line 240, that is, the second pad 320 is connected to the position with a wider width on the corresponding fourth gate line 240. Furthermore, the connection reliability between the first pad 310 and the corresponding third gate line 230 can be improved, and the connection reliability between the second pad 320 and the corresponding fourth gate line 240 can also be improved. Moreover, the first solder strip (the first solder strip is used for electrically connecting to the first pad 310) can be better utilized to collect current, and the second solder strip (the second solder strip is used for electrically connecting to the second pad 320) can also be better utilized to collect current.

[0119] In some embodiments, the dimension of the first end 2331 in the first direction F1 is 0.2 mm - 1.8 mm, and the dimension of the second end 2332 in the first direction F1 is 0.02 mm - 1.6 mm.

[0120] For example, the dimension of the first end 2331 in the first direction F1 is 0.2 mm, and the dimension of the second end 2332 in the first direction F1 is 0.02 mm; for another example, the dimension of the first end 2331 in the first direction F1 is 1.2 mm, and the dimension of the second end 2332 in the first direction F1 is 1.0 mm; for yet another example, the dimension of the first end 2331 in the first direction F1 is 1.8 mm, and the dimension of the second end 2332 in the first direction F1 is 1.6 mm.

[0121] By setting the dimension of the first end 2331 in the first direction F1 within a suitable range, such as 0.2 mm - 1.8 mm, and setting the dimension of the second end 2332 in the first direction F1 within a suitable range, such as 0.02 mm - 1.6 mm, in this way, while the third gate line 230 and the fourth gate line 240 can collect current, the resistance and manufacturing cost of the third gate line 230 and the fourth gate line 240 can also be taken into consideration.

[0122] In some embodiments, the plurality of third gate lines 230 include a first edge gate line 231 and a plurality of first intermediate gate lines 232 electrically connected to the first edge gate line 231. The plurality of fourth gate lines 240 include a second edge gate line 241 and a plurality of second intermediate gate lines 242 electrically connected to the second edge gate line 241. Along the first direction F1, the first intermediate gate lines 241 and the second intermediate gate lines 242 are alternately arranged and are located between the first edge gate line 231 and the second edge gate line 232. The first edge gate line 231 and the second intermediate gate line 242 are adjacent to each other along the first direction F1, and the second edge gate line 241 and the first intermediate gate line 232 are adjacent to each other along the first direction F1. The back contact battery 10 further includes a plurality of fifth gate lines 250 and a plurality of sixth gate lines 260 extending along the first direction F1. The fifth gate lines 250 and the sixth gate lines 260 are alternately arranged. The first gate line 210 and the fifth gate line 250 are alternately arranged along the first direction F1 and are both electrically connected to the first edge gate line 231. Along the second direction F2, the first gate line 210 and the sixth gate line 260 are alternately arranged. The second gate line 220 and the sixth gate line 260 are alternately arranged along the first direction F1 and are both electrically connected to the second edge gate line 241. Along the second direction F2, the second gate line 220 and the fifth gate line 250 are alternately arranged. A plurality of adjacent first gate lines 210 along the second direction F2 are in electrical contact with the same first intermediate gate line 232. A plurality of adjacent second gate lines 220 along the second direction F2 are in electrical contact with the same second intermediate gate line 242.

[0123] Optionally, the first gate line 210 and the fifth gate line 250 are alternately connected along the first direction F1, facilitating the synchronous formation of the plurality of first gate lines 210 and the plurality of fifth gate lines 250.

[0124] Optionally, the second gate line 220 and the sixth gate line 260 are alternately connected along the first direction F1, facilitating the synchronous formation of the plurality of second gate lines 220 and the plurality of sixth gate lines 260.

[0125] Specifically, all the first gate lines 210, all the second gate lines 220, all the fifth gate lines 250, and all the sixth gate lines 260 are respectively arranged in rows along the first direction F1 and in columns along the second direction F2.

[0126] Multiple columns of first gate lines 210 and multiple columns of second gate lines 220 are alternately arranged along the first direction F1, and one column of first gate lines 210 and an adjacent column of second gate lines 220 are arranged in a staggered manner along the second direction F2; multiple columns of fifth gate lines 250 and multiple columns of sixth gate lines 260 are alternately arranged along the first direction F1, and one column of fifth gate lines 250 and an adjacent column of sixth gate lines 260 are arranged in a staggered manner along the second direction F2. The first gate lines 210 and the fifth gate lines 250 alternately arranged along the first direction F1 are in the same row, and the second gate lines 220 and the sixth gate lines 260 alternately arranged along the first direction F1 are in the same row.

[0127] Optionally, the first gate line 210 has a first axis of symmetry parallel to the first direction F1, the fifth gate line 250 has a third axis of symmetry parallel to the first direction F1, and the first axis of symmetry of the first gate line 210 and the third axis of symmetry of the fifth gate line 250 in the same row coincide with each other.

[0128] Optionally, the first gate line 210 and the fifth gate line 250 have equal dimensions in the second direction F2.

[0129] Optionally, the second gate line 220 has a second axis of symmetry parallel to the first direction F1, the sixth gate line 260 has a fourth axis of symmetry parallel to the first direction F1, and the second axis of symmetry of the second gate line 220 and the fourth axis of symmetry of the sixth gate line 260 in the same row coincide with each other.

[0130] Optionally, the second gate line 220 and the sixth gate line 260 have equal dimensions in the second direction F2.

[0131] Optionally, the first gate line 210 and the second gate line 220 have equal dimensions in the second direction F2.

[0132] Since the first gate line 210 and the fifth gate line 250 are both electrically connected to the first edge gate line 231, and the second gate line 220 and the sixth gate line 260 are both electrically connected to the second edge gate line 241, therefore, the carriers collected by the plurality of first gate lines 210 and the plurality of fifth gate lines 250 can be collected onto the first edge gate line 231, and the carriers collected by the plurality of second gate lines 220 and the plurality of sixth gate lines 260 can also be collected onto the second edge gate line 241, thereby facilitating the outward output of current through the first edge gate line 231 and the second edge gate line 241.

[0133] Since a plurality of first gate lines 210 adjacent to each other in the second direction F2 are in electrical contact with the same first intermediate gate line 232, and a plurality of second gate lines 220 adjacent to each other in the second direction F2 are in electrical contact with the same second intermediate gate line 242. Specifically, a plurality of first gate lines 210 in the same column are in electrical contact with the same first intermediate gate line 232, and a plurality of second gate lines 220 in the same column are in electrical contact with the same second intermediate gate line 242. Therefore, a plurality of first gate lines 210 in the same column can be collected by means of the first intermediate gate line 232, and then, by virtue of the fact that the first gate line 210 and the fifth gate line 250 in the same row are electrically connected to the first edge gate line 231, in this way, the carriers collected by all the first gate lines 210 and all the fifth gate lines 250 can be collected onto the first edge gate line 231. Similarly, the carriers collected by all the second gate lines 220 and all the sixth gate lines 260 can also be collected onto the second edge gate line 241, thereby facilitating the outward output of current through the first edge gate line 231 and the second edge gate line 241.

[0134] In some embodiments, please refer to Figure 1and Figure 6 , part of the fifth grid line 250 includes a first sub-grid line 251 and a second sub-grid line 252 that are spaced apart along the first direction F1. Both the first sub-grid line 251 and the second sub-grid line 252 are electrically connected to the first grid line 210. The second intermediate grid line 242 is located between the first sub-grid line 251 and the second sub-grid line 252 of adjacent fifth grid lines 250 along the first direction F1, so as to be electrically isolated from the fifth grid line 250. The second pad 320 is located between the first sub-grid line 251 and the second sub-grid line 252 of adjacent fifth grid lines 250 along the first direction F1, so as to be electrically isolated from the fifth grid line 250.

[0135] Specifically, the second intermediate grid line 242 is located between the first sub-grid line 251 and the second sub-grid line 252 of the fifth grid lines 250 in the same column along the first direction F1, so as to be electrically isolated from these fifth grid lines 250.

[0136] In this way, the second intermediate grid line 242 can be electrically isolated from the fifth grid lines 250 in the same column, and it is convenient for the second intermediate grid line 242 to be electrically connected to the second grid lines 220 in the same column. Furthermore, while the second intermediate grid line 242 can collect the carriers collected by multiple second grid lines 220 in the same column, a clearance design between the main grid of the second intermediate grid line 242 and the opposite-sex sub-grid of the fifth grid line 250 can be realized, and a clearance design between the fifth grid line 250 and the opposite-sex pad of the second pad 320 can be realized.

[0137] It should be noted that at least one of the fifth grid lines 250 in each column does not include the first sub-grid line 251 and the second sub-grid line 252. For example, among the fifth grid lines 250 in the middle column, one of the fifth grid lines 250 does not include the first sub-grid line 251 and the second sub-grid line 252. This fifth grid line 250 is defined as the third edge grid line. In this way, the third edge grid line can be electrically connected between two adjacent first grid lines 210, and then electrically connected to the first edge grid line 231. Considering that multiple first grid lines 210 in the same column are electrically connected through the same first intermediate grid line 232, in this way, a clearance design between the main grid of the second intermediate grid line 242 and the opposite-sex sub-grid of the fifth grid line 250 can be realized, and a clearance design between the fifth grid line 250 and the opposite-sex pad of the second pad 320 can be realized, and all the first grid lines 210 and all the fifth grid lines 250 can be electrically connected to the first edge grid line 231, so as to collect the carriers collected by all the first grid lines 210 and all the fifth grid lines 250 by using the first edge grid line 231, thereby improving the current collection efficiency of the back contact battery 10.

[0138] Please refer to Figure 1 and Figure 7, a part of the sixth gate line 260 includes a third sub - gate line 261 and a fourth sub - gate line 262 which are spaced along the first direction F1. Both the third sub - gate line 261 and the fourth sub - gate line 262 are electrically connected to the second gate line 220. The first intermediate gate line 232 is located between the third sub - gate line 261 and the fourth sub - gate line 262 of adjacent sixth gate lines 260 along the first direction F1, and is electrically isolated from the sixth gate line 260; the first pad 310 is located between the third sub - gate line 261 and the fourth sub - gate line 262 of adjacent sixth gate lines 260 along the first direction F1, and is electrically isolated from the sixth gate line 260.

[0139] Specifically, the first intermediate gate line 232 is located between the third sub - gate line 261 and the fourth sub - gate line 262 of the sixth gate lines 260 in the same column along the first direction F1, and is electrically isolated from these sixth gate lines 260 from each other.

[0140] In this way, the first intermediate gate line 232 can be electrically isolated from the sixth gate lines 260 in the same column, and it is convenient for the first intermediate gate line 232 to be electrically connected to the first gate lines 210 in the same column. Furthermore, while the first intermediate gate line 232 can collect the carriers collected by multiple first gate lines 210 in the same column, an avoidance design between the main gate of the first intermediate gate line 232 and the opposite - type sub - gate of the sixth gate line 260 can be realized, and an avoidance design between the sixth gate line 260 and the opposite - type pad of the first pad 310 can be realized.

[0141] It should be noted that at least one of the sixth gate lines 260 in each column does not include the third sub - gate line 261 and the fourth sub - gate line 262. For example, among the sixth gate lines 260 in the middle column, one of the sixth gate lines 260 does not include the third sub - gate line 261 and the fourth sub - gate line 262. This sixth gate line 260 is defined as the fourth edge gate line. In this way, the fourth edge gate line can be electrically connected between two adjacent second gate lines 220, and then electrically connected to the second edge gate line 241. Combining that multiple second gate lines 220 in the same column are electrically connected through the same second intermediate gate line 242, in this way, an avoidance design between the main gate of the first intermediate gate line 232 and the opposite - type sub - gate of the sixth gate line 260 can be realized, and an avoidance design between the sixth gate line 260 and the opposite - type pad of the first pad 310 can be realized, and all second gate lines 220 and all sixth gate lines 260 can be electrically connected to the second edge gate line 241, and then the second edge gate line 241 can be used to collect the carriers collected by all second gate lines 220 and all sixth gate lines 260, thereby improving the current collection efficiency of the back - contact battery 10.

[0142] In some embodiments, please refer to Figure 1 、 Figure 6 and Figure 7The third edge grid line is located on one side of the battery cell body 100 along the second direction F2, the fourth edge grid line is located on the other side of the battery cell body 100 along the second direction F2, and the third edge grid line and the fourth edge grid line are alternately arranged along the first direction F1.

[0143] Since the third edge grid line (corresponding to the fifth grid line 250 excluding the first sub-grid line 251 and the second sub-grid line 252) is located on one side of the battery cell body 100 along the second direction F2, the third edge grid line can be used to electrically connect with the first edge grid line 231 through the adjacent first grid line 210, and it is also convenient to arrange the second intermediate grid line 242 on one side of the third edge grid line along the second direction F2, thereby facilitating the design of avoiding the second intermediate grid line 242 and the third edge grid line (the second intermediate grid line 242 and the third edge grid line are opposite grid lines to each other), and the second intermediate grid line 242 continuously arranged along the second direction F2 can also be designed so that the second intermediate grid line 242 can be electrically connected to the second grid line 220 in the same column, thereby improving the manufacturing convenience and manufacturing efficiency of the back contact battery 10.

[0144] Similarly, since the fourth edge grid line (corresponding to the sixth grid line 260 excluding the third sub-grid line 261 and the fourth sub-grid line 262) is located on the other side of the battery cell body 100 along the second direction F2, the fourth edge grid line can be used to electrically connect with the second edge grid line 241 through the adjacent second grid line 220, and it is also convenient to arrange the first intermediate grid line 232 on one side of the fourth edge grid line along the second direction F2, thereby facilitating the design of avoiding each other between the first intermediate grid line 232 and the fourth edge grid line (the first intermediate grid line 232 and the fourth edge grid line are opposite grid lines), and the first intermediate grid line 232 arranged continuously along the second direction F2 can also be designed so that the first intermediate grid line 232 can be electrically connected to the first grid line 210 in the same column, thereby improving the manufacturing convenience and manufacturing efficiency of the back contact battery 10.

[0145] In some embodiments, please refer to Figure 1 , Figure 8 and Figure 9, the back contact battery 10 further includes a seventh grid line 270 and an eighth grid line 280, and the plurality of pads further includes a plurality of third pads 330 and a plurality of fourth pads 340. Along the first direction F1, the plurality of first pads 310 and the plurality of second pads 320 are located between the plurality of third pads 330 and the plurality of fourth pads 340. The plurality of third pads 330 and the first edge grid line 231 are arranged at intervals along the first direction F1 on one side of the battery chip body 100 along the first direction F1, and the third pad 330 is electrically connected to the first edge grid line 231 through the seventh grid line 270. The plurality of fourth pads 340 and the second edge grid line 241 are arranged at intervals along the first direction F1 on the other side of the battery chip body 100 along the first direction F1, and the fourth pad 340 is electrically connected to the second edge grid line 241 through the eighth grid line 280.

[0146] Specifically, the first end portion 2331 of the first edge grid line 231 is electrically connected to the adjacent third pad 330 through the seventh grid line 270. In this way, the connection reliability between the first edge grid line 231 and the adjacent third pad 330 can be improved.

[0147] Specifically, the first end portion 2331 of the second edge grid line 241 is electrically connected to the adjacent fourth pad 340 through the eighth grid line 280. In this way, the connection reliability between the second edge grid line 241 and the adjacent fourth pad 340 can be improved.

[0148] The plurality of third pads 330 and the first edge grid line 231 are arranged at intervals along the first direction F1. In this way, the plurality of third pads 330 can be arranged in the same column and are located on the inner side of the first edge grid line 231 along the first direction F1. That is to say, the plurality of third pads 330 are at a certain distance from the side edge of the battery chip body 100 along the first direction F1. Furthermore, the connection reliability of the plurality of third pads 330 electrically connected to the corresponding first solder tape can be improved, and thus the reliability of the back contact battery 10 can be improved.

[0149] Similarly, the plurality of fourth pads 340 and the second edge grid line 241 are arranged at intervals along the first direction F1. In this way, the plurality of fourth pads 340 can be arranged in the same column and are located on the inner side of the second edge grid line 241 along the first direction F1. That is to say, the plurality of fourth pads 340 are at a certain distance from the other side edge of the battery chip body 100 along the first direction F1. Furthermore, the connection reliability of the plurality of fourth pads 340 electrically connected to the corresponding second solder tape can be improved, and thus the reliability of the back contact battery 10 can be improved.

[0150] In some embodiments, such as Figure 9As shown, the back-contact battery 10 further includes a ninth gate line 291. A plurality of fifth gate lines 250 are arranged in rows and columns. Among the columns of fifth gate lines 250 closest to the second edge gate line 241 along the first direction F1, the fifth gate line 250 including a first sub-gate line 251 and a second sub-gate line 252 is defined as a first target gate line. The first sub-gate line 251 of the first target gate line is electrically connected to the first gate line 210, and the second sub-gate line 252 of the first target gate line is electrically connected to the first gate line 210 through the adjacent ninth gate line 291 and fifth gate line 250. The fourth pad 340 is disposed between the first sub-gate line 251 and the second sub-gate line 252 of the adjacent first target gate line along the first direction F1.

[0151] Among them, the column of fifth gate lines 250 closest to the second edge gate line 241 along the first direction F1 is the fifth gate line 250 located in the edge column, and the fifth gate lines 250 in the remaining columns are the fifth gate lines 250 located in the middle column.

[0152] In this way, the column of fifth gate lines 250 closest to the second edge gate line 241 along the first direction F1 can be electrically connected together while the fifth gate lines 250 in the same column are electrically isolated from the fourth pads 340 of the opposite sex.

[0153] As Figure 8 shown, the back-contact battery 10 further includes a plurality of eleventh gate lines 293 corresponding to the plurality of third pads 330. The eleventh gate lines 293 intersect with the third pads 330 and are connected to each other. The plurality of first gate lines 210 in the same column as the third pad 330 include a plurality of first gate line groups corresponding to the plurality of third pads 330. Each first gate line group includes three first gate lines 210 spaced apart along the second direction F2. The middle one of the three first gate lines 210 in each first gate line group is connected to the third pad 330, and the remaining two first gate lines 210 in this first gate line group are located on the opposite sides of the corresponding third pad 330 along the second direction F2, and the three first gate lines 210 in each first gate line group are all electrically connected to the eleventh gate line 293.

[0154] In this way, the carriers collected by the three first gate lines 210 of the first gate line group can be collected to the eleventh gate line 293 and the corresponding third pad 330, and then collected to the first edge gate line 231.

[0155] It should be noted that the ninth gate line 291 extends along the second direction F2 and is connected between the second sub-gate line 252 of the first target gate line and the adjacent fifth gate line 250. The battery chip main body 100 is also provided with a first spacer groove C1 (as Figure 9As shown in the figure, the positive projection of the first spacer groove C1 on the cell body 100 overlaps with the positive projection of the adjacent second grid line 220 on the cell body 100, and is used to electrically isolate the second grid line 220 on one side of the corresponding fourth pad 340 in the first grid line group along the second direction F2 from the adjacent ninth grid line 291.

[0156] In some embodiments, as Figure 8 shown, the back contact cell 10 further includes a tenth grid line 292. A plurality of sixth grid lines 260 are arranged in rows and columns. Among the columns of sixth grid lines 260 closest to the first edge grid line 231 along the first direction F1, the sixth grid line 260 including the third sub-grid line 261 and the fourth sub-grid line 262 is defined as the second target grid line; the third sub-grid line 261 of the second target grid line is electrically connected to the second grid line 220, and the fourth sub-grid line 262 of the second target grid line is electrically connected to the second grid line 220 through the adjacent tenth grid line 292 and sixth grid line 260; the third pad 330 is arranged between the third sub-grid line 261 and the fourth sub-grid line 262 of the adjacent second target grid line along the first direction F1.

[0157] Among them, the column of sixth grid lines 260 closest to the first edge grid line 231 along the first direction F1 is the sixth grid line 260 located in the edge column, and the sixth grid lines 260 in the remaining columns are the sixth grid lines 260 located in the middle column.

[0158] In this way, the column of sixth grid lines 260 closest to the first edge grid line 231 along the first direction F1 can be electrically connected together while the sixth grid lines 260 in the same column are electrically isolated from the third pads 330 of the opposite sex.

[0159] As Figure 9 shown, the back contact cell 10 further includes a plurality of twelfth grid lines 294 corresponding to the plurality of fourth pads 340. The twelfth grid lines 294 intersect with the fourth pads 340 and are connected to each other. The plurality of second grid lines 220 in the same column as the fourth pads 340 include a plurality of second grid line groups corresponding to the plurality of fourth pads 340. Each second grid line group includes three second grid lines 220 spaced apart along the second direction F2. The middle one of the second grid lines 220 in each second grid line group is connected to the fourth pad 340, and the remaining two second grid lines 220 in the second grid line group are located on the opposite sides of the corresponding fourth pad 340 along the second direction F2, and the three second grid lines 220 in each second grid line group are all electrically connected to the twelfth grid line 294.

[0160] In this way, the carriers collected by the three second grid lines 220 in the second grid line group can be collected to the twelfth grid line 294 and the corresponding fourth pad 340, and then collected to the second edge grid line 241.

[0161] It should be noted that the tenth grid line 292 extends along the second direction F2 and is connected between the fourth sub-grid line 262 of the second target grid line and the adjacent sixth grid line 260. The battery cell body 100 is further provided with a second spacer groove C2 (as Figure 8 shown), the orthographic projection of the second spacer groove C2 on the battery cell body 100 overlaps with the orthographic projection of the adjacent first grid line 210 on the battery cell body 100, and is used to electrically isolate the first grid line 210 on one side of the corresponding fourth pad 340 in the second grid line group along the second direction F2 from the adjacent tenth grid line 292.

[0162] In some embodiments, please refer to Figure 1 , Figure 10 and Figure 11 . The back-contact battery 10 further includes at least two positioning marks 400 provided on the battery cell body 100. The plurality of first grid lines 210 and the plurality of second grid lines 220 are arranged on the battery cell body 100 at preset positions by means of the at least two positioning marks 400; the at least two positioning marks 400 are symmetrically distributed with the first preset plane P1 as the reference object; the distance between the centers of two adjacent positioning marks 400 along the first direction F1 is the first preset distance; in two back-contact batteries 10 symmetrically arranged with the second preset plane P2, the distance between the centers of two adjacent positioning marks 400 along the second direction F2 is the second preset distance; wherein, the first preset plane P1 is perpendicular to the first direction F1, the second preset plane P2 is perpendicular to the second direction F2, the first direction F1 and the second direction F2 intersect with each other, and both are perpendicular to the thickness direction of the battery cell body 100.

[0163] Optionally, the first preset distance is 110 mm - 130 mm. For example, the first preset distance is 110 mm, 120 mm or 130 mm.

[0164] Optionally, the second preset distance is 110 mm, 120 mm or 130 mm.

[0165] The at least two positioning marks 400 can be designed according to the size of the battery cell body 100 in the plane direction and the layout requirements of the plurality of first grid lines 210 and the plurality of second grid lines 220, so that the plurality of first grid lines 210 and the plurality of second grid lines 220 are arranged on the battery cell body 100 at preset positions by means of the at least two positioning marks 400, and the position accuracy of the plurality of first grid lines 210 and the plurality of second grid lines 220 on the battery cell body 100 is improved.

[0166] In some embodiments, at least two positioning marks 400 include at least two first positioning marks 410 and at least two second positioning marks 420. The preset positions include a first preset position corresponding to a plurality of first grid lines 210 and a second preset position corresponding to a plurality of second grid lines 220. The plurality of first grid lines 210 are disposed on the battery cell body 100 at the first preset position by means of at least two first positioning marks 410, and the plurality of second grid lines 220 are disposed on the battery cell body 100 at the second preset position by means of at least two second positioning marks 420.

[0167] The position accuracy of the plurality of first grid lines 210 on the battery cell body 100 can be improved by using at least two first positioning marks 410, and the position accuracy of the plurality of second grid lines 220 on the battery cell body 100 can also be improved by using at least two second positioning marks 420.

[0168] In some embodiments, the orthographic projection of the positioning mark 400 on the battery cell body 100 is configured as a circle, and the diameter of the circle is 0.01 mm - 2 mm.

[0169] Exemplarily, the diameter of the circle is 0.01 mm, 0.5 mm, 1 mm or 2 mm.

[0170] Setting the diameter of the circle within a suitable range is beneficial for positioning with reference to the center of the positioning mark 400 and does not affect the layout of grid lines such as the first grid line 210 and the second grid line 220.

[0171] In some embodiments, the plurality of first grid lines 210 are arranged in rows and columns. The first grid line 210 has a first axis of symmetry parallel to the first direction F1, and the orthographic projection of the center of the first positioning mark 410 on the battery cell body 100 coincides with the orthographic projection of the first axis of symmetry of the corresponding row of first grid lines 210 on the battery cell body 100.

[0172] In this way, the first grid lines 210 can be symmetrically arranged relative to the first positioning marks 410, which is beneficial for improving the position accuracy of the plurality of first grid lines 210 on the battery cell body 100.

[0173] In some embodiments, the plurality of second grid lines 220 are arranged in rows and columns. The second grid line 220 has a second axis of symmetry parallel to the first direction F1. The orthographic projection of the center of the second positioning mark 420 on the battery cell body 100 coincides with the orthographic projection of the second axis of symmetry of the corresponding row of second grid lines 220 on the battery cell body 100.

[0174] In this way, the second grid lines 220 can be symmetrically arranged relative to the second positioning marks 420, which is beneficial for improving the position accuracy of the plurality of second grid lines 220 on the battery cell body 100.

[0175] In some embodiments, the back contact battery 10 further includes an insulating layer. The insulating layer includes a first insulating portion 510 corresponding to each of the plurality of fifth gate lines 250, a second insulating portion 520 corresponding to each of the plurality of sixth gate lines 260, a third insulating portion 530 corresponding to each of the plurality of first spacer grooves C1, and a fourth insulating portion 540 corresponding to each of the plurality of second spacer grooves C2. The first insulating portion 510 covers the side of the corresponding fifth gate line 250 facing away from the battery cell body 100. The second insulating portion 520 covers the side of the corresponding sixth gate line 260 facing away from the battery cell body 100. The third insulating portion 530 is disposed in the corresponding first spacer groove C1 and covers the side of the corresponding ninth gate line 291 facing away from the battery cell body 100. The fourth insulating portion 540 is disposed in the corresponding second spacer groove C2 and covers the side of the corresponding tenth gate line 292 facing away from the battery cell body 100.

[0176] Specifically, the third insulating portion 530 is connected between two adjacent first insulating portions 510 along the second direction F2, and the fourth insulating portion 540 is connected between two adjacent second insulating portions 520 along the second direction F2.

[0177] During the process of welding the corresponding first solder tape to the first pad 310 or during the process of welding the corresponding first solder tape to the third pad 330, the second insulating portion 520 can be used to electrically isolate the sixth gate line 260 in the same column as the first pad 310 or the third pad 330 from the dissimilar solder tape (i.e., the first solder tape), so as to avoid short circuit problems caused by the electrical connection between the sixth gate line 260 and the dissimilar solder tape.

[0178] Similarly, during the process of welding the corresponding second solder tape to the second pad 320 or during the process of welding the corresponding second solder tape to the fourth pad 340, the first insulating portion 510 can be used to electrically isolate the fifth gate line 250 in the same column as the second pad 320 or the fourth pad 340 from the dissimilar solder tape (i.e., the second solder tape), so as to avoid short circuit problems caused by the electrical connection between the fifth gate line 250 and the dissimilar solder tape.

[0179] Similarly, during the process of welding the corresponding first solder tape to the third pad 330, the fourth insulating portion 540 can be used to electrically isolate the tenth gate line 292 in the same column as the third pad 330 from the dissimilar solder tape (i.e., the first solder tape), so as to avoid short circuit problems caused by the electrical connection between the tenth gate line 292 and the dissimilar solder tape.

[0180] Similarly, during the process of soldering the corresponding second solder tape to the fourth pad 340, the third insulating portion 530 can be used to electrically isolate the ninth grid line 291 in the same column as the fourth pad 340 from the dissimilar solder tape (i.e., the second solder tape), avoiding short - circuit problems caused by the electrical connection between the ninth grid line 291 and the dissimilar solder tape. An embodiment of the present application provides a photovoltaic module, including a battery string, and the battery string includes a plurality of back - contact batteries 10 according to any one of the above - mentioned embodiments.

[0181] It should be noted that the above - mentioned back - contact battery 10 is a half - cell, and a plurality of back - contact batteries 10 are connected in series through a plurality of first solder tapes and a plurality of second solder tapes to form a battery string.

[0182] Among them, all the first solder tapes are respectively arranged corresponding to all the first pads 310 and all the third pads 330. A plurality of first pads 310 in the same column are all electrically connected to a corresponding first solder tape, and a plurality of third pads 330 in the same column are all electrically connected to another corresponding first solder tape. All the second solder tapes are respectively arranged corresponding to all the second pads 320 and all the fourth pads 340. A plurality of second pads 320 in the same column are all electrically connected to a corresponding second solder tape, and a plurality of fourth pads 340 in the same column are all electrically connected to another corresponding second solder tape.

[0183] In this way, for two adjacent back - contact batteries 10, a plurality of first solder tapes of one back - contact battery 10 can be electrically connected to a plurality of second solder tapes of another back - contact battery 10 through busbars. In this way, a plurality of back - contact batteries 10 can be connected in series to form a battery string.

[0184] The technical features of the above - mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above - mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0185] The above - mentioned embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A back-contact battery, characterized in that, Comprising: A main body of a solar cell, along the thickness direction perpendicular to the main body of the solar cell, the main body of the solar cell has a front side and a back side arranged opposite to each other; A plurality of first grid lines and a plurality of second grid lines, disposed on the back side, and the first grid lines and the second grid lines are alternately arranged; And A plurality of pads, disposed on the back side, and including a plurality of first pads and a plurality of second pads; the first pads are electrically connected to the first grid lines, and the second pads are electrically connected to the second grid lines; Wherein, the plurality of first pads include a first test pad, and the first test pad is in electrical contact with at least two adjacent first grid lines; The plurality of second pads include a second test pad, and the second test pad is in electrical contact with at least two adjacent second grid lines.

2. The back contact battery according to claim 1, characterized in that, The plurality of pads are arranged in rows and columns; the pads are provided with n columns, and the first test pad is located in at least one column among the 2nd column to the (n - 1)th column; the second test pad is located in at least one column among the 2nd column to the (n - 1)th column and is in a different column from the first test pad; wherein, n is a positive integer, 10 ≤ n ≤ 20; and / or The plurality of pads are arranged in rows along a first direction and in columns along a second direction; the pads are provided with m rows; the main body of the solar cell has a straight side and a chamfered side oppositely arranged along the second direction; along the direction from the chamfered side to the straight side, the first test pad is located in one row among the 2nd row to the mth row; the second test pad is located in one row among the 2nd row to the mth row; wherein, m is a positive integer, 2 ≤ m ≤ 6; and / or The plurality of first pads further include a plurality of first connection pads; the orthographic projection area of the first test pad on the main body of the solar cell is larger than the orthographic projection area of the first connection pad on the main body of the solar cell; and / or The plurality of second pads further include a plurality of second connection pads; the orthographic projection area of the second test pad on the main body of the solar cell is larger than the orthographic projection area of the second connection pad on the main body of the solar cell; Wherein, the first direction and the second direction intersect with each other and are both perpendicular to the thickness direction of the main body of the solar cell.

3. The back-contact battery according to claim 1, characterized in that, The first grid lines and the second grid lines both extend along the first direction; the plurality of first pads further include a plurality of first connection pads; the dimension of the first test pad in the second direction is larger than the dimension of the first connection pad in the second direction; the plurality of second pads further include a plurality of second connection pads; the dimension of the second test pad in the second direction is larger than the dimension of the second connection pad in the second direction; wherein, the first direction and the second direction intersect with each other and are both perpendicular to the thickness direction of the main body of the solar cell; The dimension of the first test pad in the second direction is 2 mm - 4 mm, and the dimension of the first test pad in the first direction is 0.2 mm - 3.0 mm; and / or The dimension of the second test pad in the second direction is 2 mm - 4 mm, and the dimension of the second test pad in the first direction is 0.2 mm - 3.0 mm; and / or The multiple first pads include multiple first connection pads; the size of the first connection pad in the second direction is 0.3 mm - 3.0 mm, and the size of the first connection pad in the first direction is 0.2 mm - 3.0 mm; and / or The multiple second pads include multiple second connection pads; the size of the second connection pad in the second direction is 0.3 mm - 3.0 mm, and the size of the second connection pad in the first direction is 0.2 mm - 3.0 mm.

4. The back-contact battery according to claim 1, wherein The back-contact battery further includes multiple third grid lines and multiple fourth grid lines; the third grid lines and the fourth grid lines are alternately arranged along the first direction on the back surface of the battery cell body and both extend along the second direction; the first grid line and the second grid line both extend along the first direction; the third grid line is electrically connected to the first grid line; the fourth grid line is electrically connected to the second grid line; wherein, the first direction and the second direction intersect with each other and are both perpendicular to the thickness direction of the battery cell body.

5. The back-contact battery according to claim 4, wherein Both the third grid line and the fourth grid line include multiple first parts connected along the second direction; The first part has a first end and a second end oppositely arranged along the second direction; The size of the first end in the first direction is different from the size of the second end in the first direction; Two adjacent first ends among two adjacent first parts are connected; or two adjacent second ends among two adjacent first parts are connected.

6. The back contact battery according to claim 5, wherein, The size of the first end in the first direction is greater than the size of the second end in the first direction; The orthographic projection of the first end on the target plane overlaps with the orthographic projection of the corresponding pad on the target plane; the orthographic projection of the second end on the target plane is staggered from the orthographic projection of the corresponding pad on the target plane; the target plane is perpendicular to the thickness direction of the battery cell body; The size of the first end in the first direction is 0.2 mm - 1.8 mm, and the size of the second end in the first direction is 0.02 mm - 1.6 mm.

7. The back-contact battery according to claim 4, characterized in that, The multiple third grid lines include a first edge grid line and multiple first intermediate grid lines electrically connected to the first edge grid line, the multiple fourth grid lines include a second edge grid line and multiple second intermediate grid lines electrically connected to the second edge grid line, along the first direction, the first intermediate grid lines and the second intermediate grid lines are alternately arranged and are located between the first edge grid line and the second edge grid line; The back-contact battery further includes multiple fifth grid lines and multiple sixth grid lines extending along the first direction, the fifth grid lines and the sixth grid lines are alternately arranged; The first grid line and the fifth grid line are alternately arranged along the first direction and are both electrically connected to the first edge grid line; along the second direction, the first grid line and the sixth grid line are alternately arranged; The second gate line and the sixth gate line are alternately arranged along the first direction, and are both electrically connected to the second edge gate line; along the second direction, the second gate line and the fifth gate line are alternately arranged; A plurality of adjacent first gate lines along the second direction are in electrical contact with the same first intermediate gate line; A plurality of adjacent second gate lines along the second direction are in electrical contact with the same second intermediate gate line.

8. The back-contact battery according to claim 7, characterized in that, Part of the fifth gate lines include a first sub-gate line and a second sub-gate line which are spaced apart along the first direction; the first sub-gate line and the second sub-gate line are both electrically connected to the first gate line; the second intermediate gate line is located between the first sub-gate line and the second sub-gate line of the adjacent fifth gate lines along the first direction, so as to be electrically isolated from the fifth gate line; the second pad is located between the first sub-gate line and the second sub-gate line of the adjacent fifth gate lines along the first direction, so as to be electrically isolated from the fifth gate line; Part of the sixth gate lines include a third sub-gate line and a fourth sub-gate line which are spaced apart along the first direction; the third sub-gate line and the fourth sub-gate line are both electrically connected to the second gate line; the first intermediate gate line is located between the third sub-gate line and the fourth sub-gate line of the adjacent sixth gate lines along the first direction, so as to be electrically isolated from the sixth gate line; the first pad is located between the third sub-gate line and the fourth sub-gate line of the adjacent sixth gate lines along the first direction, so as to be electrically isolated from the sixth gate line.

9. The back contact battery according to claim 8, wherein, The back contact battery further includes a seventh gate line and an eighth gate line; the plurality of pads further include a plurality of third pads and a plurality of fourth pads; along the first direction, the plurality of first pads and the plurality of second pads are located between the plurality of third pads and the plurality of fourth pads; the plurality of third pads and the first edge gate line are alternately arranged along the first direction on one side of the battery chip body along the first direction, and the third pad is electrically connected to the first edge gate line through the seventh gate line; the plurality of fourth pads and the second edge gate line are alternately arranged along the first direction on the other side of the battery chip body along the first direction, and the fourth pad is electrically connected to the second edge gate line through the eighth gate line.

10. The back-contact battery according to claim 9, characterized in that, The back contact battery further includes a ninth gate line; the plurality of fifth gate lines are arranged in rows and columns. Among the columns of the fifth gate lines closest to the second edge gate line along the first direction, the fifth gate line including the first sub-gate line and the second sub-gate line is defined as a first target gate line. The first sub-gate line of the first target gate line is electrically connected to the first gate line, and the second sub-gate line of the first target gate line is electrically connected to the first gate line through the adjacent ninth gate line and fifth gate line; the fourth pad is arranged between the first sub-gate line and the second sub-gate line of the adjacent first target gate line along the first direction; and / or The back contact battery further includes a tenth grid line; the plurality of sixth grid lines are arranged in rows and columns, and among the columns of the sixth grid lines closest to the first edge grid line along the first direction, the sixth grid lines including the third sub-grid line and the fourth sub-grid line are defined as second target grid lines; the third sub-grid line of the second target grid line is electrically connected to the second grid line, and the fourth sub-grid line of the second target grid line is electrically connected to the second grid line through the adjacent tenth grid line and sixth grid line; the third pad is arranged between the third sub-grid line and the fourth sub-grid line of the adjacent second target grid line along the first direction.

11. The back contact battery according to any one of claims 1-10, characterized in that, The back contact battery further includes at least two positioning marks provided on the main body of the battery cell. The plurality of first grid lines and the plurality of second grid lines are arranged on the main body of the battery cell at preset positions by means of the at least two positioning marks. The at least two positioning marks are symmetrically distributed with a first preset plane as a reference object. The distance between the centers of two adjacent positioning marks along the first direction is a first preset distance. In two back contact batteries symmetrically arranged with a second preset plane, the distance between the centers of two adjacent positioning marks along the second direction is a second preset distance. Wherein, the first preset plane is perpendicular to the first direction, the second preset plane is perpendicular to the second direction, the first direction and the second direction intersect with each other, and both are perpendicular to the thickness direction of the main body of the battery cell. The first preset distance is 110 mm - 130 mm. The second preset distance is 110 mm - 130 mm.

12. The back-contact battery according to claim 11, wherein, The at least two positioning marks include at least two first positioning marks and at least two second positioning marks. The preset positions include a first preset position corresponding to the plurality of first grid lines and a second preset position corresponding to the plurality of second grid lines; the plurality of first grid lines are arranged on the main body of the battery cell at the first preset position by means of the at least two first positioning marks; the plurality of second grid lines are arranged on the main body of the battery cell at the second preset position by means of the at least two second positioning marks. and / or The orthographic projection of the positioning mark on the main body of the battery cell is configured as a circle, and the diameter of the circle is 0.01 mm - 2 mm. and / or The plurality of first grid lines are arranged in rows and columns; the first grid line has a first axis of symmetry parallel to the first direction; the orthographic projection of the center of the first positioning mark on the main body of the battery cell coincides with the orthographic projection of the first axis of symmetry of the corresponding row of the first grid lines on the main body of the battery cell; and / or The plurality of second grid lines are arranged in rows and columns; the second grid line has a second axis of symmetry parallel to the first direction. The orthographic projection of the center of the second positioning mark on the main body of the battery cell coincides with the orthographic projection of the second axis of symmetry of the corresponding row of the second grid lines on the main body of the battery cell.

13. A photovoltaic module, characterized in that, A battery string is included, and the battery string includes a plurality of back contact batteries according to any one of claims 1 - 12.

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